Setting Sag

Setting Sag on air forks and shocks is simple with a little help from a friend.

You will need:

  • Shock pump
  • Metric tape measure
  • Rubber band (If missing rubber O-ring)
  • Be dressed in full riding gear (hydration pack if you wear one)

It’s important to have your full riding gear on– as the weight of what you wear will need to be factored into the ‘rider weight’ and the suspension sag will need to be set accordingly. So it might be a good idea to make adjustments just before you ride, and take the shock pump with you so you can make further adjustments.

1. It’s a good idea to have someone to help, but it’s possible to set sag yourself by leaning against a wall or solid object.  

2. Start by measuring the stanchion of the fork, the shiny bit that moves inside the larger leg. Divide that length by four to calculate a 25% sag distance. Some more aggressive forks, such as those found on downhill bikes, can be set with up to 15-30 percent sag, but if you’re not sure, use 25%.

3. Repeat above process for the rear shock. Most rear shocks will need sag set between 20-30%, but if you’re not sure use 25%.

3. Get on the bike and assume the riding position. Most forks and shocks will have a small rubber ring on one of the legs or on the shock shaft, which will allow you to see the amount of sag – if yours hasn’t, you can tie a rubber band around the leg.

4. Get on the bike and compress the suspension to reduce any friction. Slide O-ring towards shock body and carefully get off the bike without adding any additional load. 

Adjust the air pressure until the desired 15-30% sag is achieved. 15-20% on the fork and 20-30% on the rear shock.  You can check the website of your shock manufacture of specifics of sag recommendations. If you have an air fork, take it up or down by roughly 5 psi at a time, or for coil forks, a full turn at a time should give the right increments.


Set Rebound and Compression

Start by working out how many ‘clicks’ of range you have in the dial. To do this, wind the dial fully in clockwise, then wind it back out. As you wind it out, count the clicks.

If you aren’t sure what you need, or have a new shock, you’d be well advised to set the dials to the middle of the range. You can then experiment by one or two clicks at a time, either way, until the desired setup is achieved.

It’s quite rare that taking either compression or rebound to the extremes will have much benefit, so most riders will want to stay near the midpoint.